Furnace for reducing and smelting nickel oxids.



PATENTBD NOV. 8, 1904.

R. R. MAFPETT. FURNAGE FOR REDUCING AND SMELTING NICKEL OXIDS.

APPLICATION FILED 3111.29, 1903.

N0 MODEL.

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UNTTED STATES Patented November 8, 1904.

PATENT OEEicE.

ROBERT R. MAFFETT, OF BAYONNE, NEW JERSEY, ASSIGNOR 'IO INTER- NATIONALNICKEL COMPANY, A CORPORATION OF NEW JERSEY.

FURNACE FOR REDUCING AND SMELTING NICKEL OXIDS.

SPEOIFICATIONforming part of Letters Patent N0. 774,591, dated November8,. 1904. Application filed January 29, 1903. Serial No. 141,006. (Nomodel.)

To It whom itmcty concern:

Be it known that 1, ROBERT R. MAFFETT, of Bayonne, in the county ofHudson and State of New Jersey, have invented a new and useful Furnacefor Reducing and Smelting Nickel Oxids, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings, forming part of this specification, in whichFigure 1 is a vertical sectional view of a furnace embodying myinvention. Figs. 2 and 3 are vertical sections on the lines II II andIII III, respectively.

The furnace which is the subject of my invention is designed for thereduction and smelting of nickel oxid by subjecting the oxid to thefollowing successive steps: first, roasting of the oxid in admixturewith carbon, by which the oxid is reduced partially to metal, and.second, smelting the oxid and metal on the hearth of a smelting-chamber,by which the reduction is completed and the oxid reduced to metallicnickel which can be withdrawn from the smelting-chamber and cast intomolds. My invention enables both of these operations to be carried on ina single furnace with a very great saving of fuel and labor and acorresponding lesseningof the cost of the finished product.

As shown in the drawings, heat is supplied to the furnace by burners 22,- adapted to burn oil; but gas burners or fines discharging burninggases into the furnace from a combustion-chamber may be substituted, ifdesirec.

3 is the smelting-chamber, into which the flame from the burners entersdirectly. Its hearth is of suitable area to receive the charge of oxidto be smelted, and it is provided with openings 4: 4:, preferably in theroof, for the introduction of the charge, with a tap-hole 5 for thewithdrawal of the fused nickel and with suitable working doors 6 6.

At the rear end of the smelting-chamber and beyond the bridge-wall 7 isa muffie or reducing chamber 8, which is a long chamber communicating atits front end over the bridgewall 7 with the smelting-chamber andcommunicating at its rear end with the stack-fine 9. Tile-dampers 10 areprovided, preferably, at both ends, by which the chamber may whendesired be cut ofi from the stack-flue and the smelting-chamber. Workingdoors 11 are formed at its sides, and charging-doors 12 are provided,preferably, in the roof, though, if desired, the charge to be reducedmay be introduced through the side working doors.

Below the reducing-chamber arc flu cs 13 18, one or more in number,which at the front end communicate with the smelting-chamber over thebridge-wall and at the rear end discharge into the stack-fine. It willthus. be seen that the flame and products of combustion from thesmelting-chamber after passing the bridgewall are divided, part passingthrough the reducing-chamber and part passing through the fiues beneaththe reducingchamber, and that by adjustment of the dampers 10, or eitherof them, any desired proportion of the gases can be diverted through thefines or by shutting the dampers, or either of them, all of the gasesmay be caused to pass through said fines.

To charge the reducing-chamber with the mixture of oxid and carbon whichis to be spread over the fioor of the chamber, I prefer to employ anelevated track 14, extending along and above the reducing-chamber andextending also above the smelting-chamber -for the charging of thelatter, An elevator 15 may be used for raising the charging-cars to theelevated track, and tracks 16 extend along the reducing-chamber at thegroundlevel for the cars, into which the reduced charge may be withdrawnwhen ready to be charged into the smelting-chamber.

In the operation of the furnaces a mixture of nickel oxid and groundcharcoal, preferably in the proportion ofnine parts, in weight, ofnickel oxid to one part of charcoal, is charged into thereducing-chamber and spread over the bottom thereof. In order to excludethe chamber from communication with the stackfi ue, and thus prevent alldrafts which would tend to carry off part of the charge, the dampers 1010 are closed during the time of charging. When the reducing-chamber hasbeen thus charged, the dampers are opened, and the flame from theburners heats the charge in the smelting-chamber, then passes throughand under the reducing-chamber, heating the charge therein toincandeseence, until, finally-say, at the end of five hours for asix-ton charge-the oxid has been sufl iciently reduced, care being takenby adjustment of the dampers to prevent the heat in the reducing-chamberfrom becoming so high as to melt the charge. When the desired extent ofreduction has been effected, the dampers 10 10 are again closed, so asto exclude the reducing-chamber from the draft of the stack, and thereduced charge, if not needed immediately for the smelting-chamber, isheaped at the end of the reducingchamber, where it is kept hot untilneeded; but when needed for the smelting-chamber it is withdrawn throughthe working doors 11 into the cars on the tracks 16 beside the furnace.These cars are drawn to the elevator 15, hoisted to the elevated track14:, drawn to the smelting-furnace 2, and their contents droppedthereinto through the openings normally closed by the doors 4:. A newcharge of mixed oxid and carbon is then charged into thereducing-furnace and spread over the floor, the dampers 1O 10 meanwhilebeing closed, as stated above. The charge for the smelting-chamber ispreferably added in two or more lots because of the lessening of itsbulk which occurs as it melts down. Thus ten thousand pounds of thepartly-reduced oxid, with its admixed carbon, may be first charged. Atthe end of three hours three thousand pounds more may be introduced, andafter five to seven hours thereafter the whole charge, being melted andreduced to metallic state, can be tapped into molds. During the smeltingoperation the waste heat from the smelting-chamber passes, as beforestated,

through the flues 13 and through the reducing-chamber and raises themixture of oxid and carbon to incandesence, so that the operations inboth the smelting-chamber and the red ucing-chamber are carried onsimultaneously, at the end of each heat the smelted charge be ing tappedfrom the smelting-chamber and a reducedcharge transferred to thesmeltingchamber, new charges of oxid and carbon being fed to thereducing-chamber from time to time. In this way I am enabled Without theuse of extra fuel to carry on the reduction of the oxid by the wasteheat from the smelting operation. The economy of fuel, the compactnessof furnace structure, and the lessening of labor which thus resulteffect a very great saving in the cost of finished product.

Within the scope of my invention as defined in the claims the furnacemay be modified, since What I claim is- 1. A furnace having anopen-hearth smelting-chamber, an elongated reducing-chamber leadingtherefrom, charging-openings for said reducing-ehamber arrangedlengthwise thereof, a flue extending beneath the reducingchamber, and astacl;-flue with which the red ucing-chamber and flue communicate attheir rear ends; substantially as described.

2. Afurnace having an open-hearth smelting-chamber, an elongatedreducing-chamber leading therefrom, charging-openings for saidreducing-chamber arranged lengthwise thereof, a flue extending beneaththe reducingehamber, a stack-flue with which the reducing-chamber andflue communicate at their rear ends, and a damper for thereducingchamber; substantially as described.

3. A furnace having an open-hearth smelting-chamber, an elongatedreducing-chamber leading therefrom, charging-openings for saidreducing-chamber arranged lengthwise thereof, a flue extending beneaththe reducingchamber, a stack-flue with which the reducing-chamber andflue communicate at their rear ends, and a damper at each end of the reducing-chamber; substantially asdescribed.

In testimony whereof I have hereunto set my hand.

ROBERT R. MAFFETT.

\Vitn esses:

AMBROSE MoxnLL,

B. B, GATTELL.

